Update Site Health to use `do_accordion_sections()`

[joedolson]

Currently, the do_accordion_sections() function is used in only one place - the navigation menus. However, the same pattern and JS is used in Site Health, as well.

This has a lot to do with how the function is set up, which is limiting to its effective use. It's completely dependent on the presence of meta boxes, and has no flexibility for other usage.

Site Health, on the other hand, uses a combination of Underscore JS templates to render the content.

This ticket is to explore the possibility of using the same codebase to output these two accordion patterns and reduce code duplication.

See #42002.